Microbial activity and particulate matter in the benthic nepheloid layer (BNL) of the deep Arabian Sea

Boetius, Antje; Springer, Barbara; Petry, Carolin

doi:10.1016/s0967-0645(00)00045-x

Cited by 35 publications

(28 citation statements)

References 37 publications

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“…Although other studies have reported higher bacterial concentrations in benthic boundary or nepheloid layers compared with adjacent particle-poor waters (Ritzrau et al 1997;Boetius et al 2000), we did not observe statistically different concentrations either in 2000 (Wells and Deming 2003) or in 2002. Instead of correlating with any of the particulate variables that distinguished nepheloid and nonnepheloid waters, total cell concentrations in these subsurface waters were best explained by organic carbon freshness (Chl a : POC ratio).…”

Section: Discussioncontrasting

confidence: 99%

“…These particlerich waters might be important not only in terms of sediment transport but as sites of microbially mediated organic transformations. The latter possibility is consistent with observations of increased microbial activity in nepheloid layers (e.g., Townsend et al 1992;Boetius et al 2000) and sinking particles (e.g., Huston and Deming 2002) in other marine environments, as well as the often disproportionate contribution of particle-associated bacteria to bacterial secondary production in estuaries (Griffith et al 1994;Crump et al 1998). The likely biogeochemical significance of particlerich waters is an argument for understanding the composition of their microbial inhabitants (the subject of parallel work in surface waters of the region; Garneau et al unpubl.…”

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confidence: 91%

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Archaea in particle-rich waters of the Beaufort Shelf and Franklin Bay, Canadian Arctic: Clues to an allochthonous origin?

et al. 2006

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We used 4Ј,6-diamidino-2-phenylindole (DAPI) staining and fluorescent in situ hybridization to examine total bacterioplankton and archaeal distributions in surface waters and in deeper nepheloid layers and particle-poor waters across the Beaufort Shelf of the Canadian Arctic, including the Mackenzie River and Kugmallit Bay, as well as more distant Franklin Bay. Although the regional distribution of bacterioplankton was best explained by salinity (r s ϭ Ϫ0.89, n ϭ 28, p Ͻ 0.001) and indicators of primary production (chlorophyll a [Chl a], total organic carbon, and the ratio of Chl a to particulate organic carbon [Chl a : POC]), that of Archaea instead reflected measures of particulate matter, specifically microscopically determined particle concentration (r s ϭ 0.85, n ϭ 30, p Ͻ 0.001), suspended particulate matter, POC, particulate organic nitrogen (PON), and the beam attenuation coefficient. Moreover, when compared with similarly deep particle-poor waters, nepheloid layers were significantly enriched in Archaea (median concentration of 6.00 ϫ 10 4 mL Ϫ1 [15.5% of bacterioplankton] vs. 1.79 ϫ 10 4 mL Ϫ1 [3.6%]; p Ͻ 0.05), but not total bacterioplankton. The relationship between Archaea and particles, the dominance of the Mackenzie River as the regional particle source, the detection of highest archaeal concentrations (11.5-14.4 ϫ 10 4 mL Ϫ1) in the river, and the highly significant correlation (r s ϭ 0.97, n ϭ 12, p Ͻ 0.001) between Archaea in particle-rich waters and PON (the river providing the upper end member) suggest that many of these Archaea derive from the river.Archaea have now been recognized as ubiquitous and sometimes abundant members of the marine bacterioplank-1 Corresponding author (chimera1@ocean.washington.edu). 2 Present address: Department of Bioengineering, Rice University, Houston, Texas 77005.3 Present address: Department of Biology, University of Washington, Seattle, Washington 98195. AcknowledgmentsWe thank the officers and crew of the NGCC Pierre Radisson, Louis Fortier for leadership of the Canadian Arctic Shelf Exchange Study (CASES), and Martin Fortier for his work as chief scientist. We also thank J.-E. Tremblay (Laval University, Quebec) for generously providing us with nutrient data, S. Demers and K. Lacoste (University of Quebec at Rimouski) for the POC, PON, and Chl a data, and Y. Gratton (INRS-Eau, Terre et Environnement, University of Quebec) for the CTD and transmissivity profiles. We appreciated the hard work of the water column sampling team of G. Desmeules, E. Rail, F. Bazinet, and M. Robert and the TOC analyses of Nes Sutherland. T. Papakyriakou (University of Manitoba) kindly discussed wind data with us, and C. Lovejoy (Laval University) commented on an early version of this manuscript. We acknowledge with gratitude the availability of the Ribosomal Database Project II Versions 8.1 and 9.0, as maintained by Michigan State University. Finally, we thank S. Carpenter (University of Washington [UW]) for assistance preparing figures, E. Lessard (UW) for discussion, and...

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Section: Discussioncontrasting

confidence: 99%

supporting

confidence: 91%

Archaea in particle-rich waters of the Beaufort Shelf and Franklin Bay, Canadian Arctic: Clues to an allochthonous origin?

et al. 2006

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“…The large relative increase of detritus in the bottom water compared to the overlying grid box exhibited by model CTL seems to be rather high when compared to observations, but model BUR with its less pronounced particle increase seems to be more in line with observations of a several-fold increase of particle number or mass taken e.g by Boetius et al (2000), McCave et al (2001), or Lukashin and Shcherbinin (2007). Note that despite the several fold increase of detritus concentration relative to the overlying water, the absolute concentrations in deep bottom waters are mostly at nanomolar levels.…”

Section: Combining Model Metricssupporting

confidence: 60%

Swept under the carpet: organic matter burial decreases global ocean biogeochemical model sensitivity to remineralization length scale

Kriest

Oschlies

2013

Biogeosciences

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Abstract. Although of substantial importance for marine tracer distributions and eventually global carbon, oxygen, and nitrogen fluxes, the interaction between sinking and remineralization of organic matter, benthic fluxes and burial is not always represented consistently in global biogeochemical models. We here aim to investigate the relationships between these processes with a suite of global biogeochemical models, each simulated over millennia, and compared against observed distributions of pelagic tracers and benthic and pelagic fluxes.We concentrate on the representation of sediment-water interactions in common numerical models, and investigate their potential impact on simulated global sediment-water fluxes and nutrient and oxygen distributions. We find that model configurations with benthic burial simulate global oxygen well over a wide range of possible sinking flux parameterizations, making the model more robust with regard to uncertainties about the remineralization length scale. On a global scale, burial mostly affects oxygen in the meso-to bathypelagic zone. While all model types show an almost identical fit to observed pelagic particle flux, and the same sensitivity to particle sinking speed, comparison to observational estimates of benthic fluxes reveals a more complex pattern, but definite interpretation is not straightforward because of heterogeneous data distribution and methodology. Still, evaluating model results against observed pelagic and benthic fluxes of organic matter can complement model assessments based on more traditional tracers such as nutrients or oxygen. Based on a combined metric of dissolved tracers and biogeochemical fluxes, we here identify two model descriptions of burial as suitable candidates for further experiments and eventual model refinements.

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“…That 1 water column profile ( Fig. 2A) Other studies have suggested that nepheloid layers can be nutritionally enriched environments compared to the surface or adjacent deep waters (Kamykowski & Bird 1981, Checkley et al 1992, Boetius et al 2000. Benthic nepheloid layers examined in the Gulf of Maine (Townsend et al 1992), Kiel Bight (Ritzrau & Graf 1992), the deep Arabian Sea (Boetius et al 2000) and the Northeast Water, an Arctic polynya , all supported greater bacterial abundance and/or biomass relative to nearby deep waters.…”

Section: Nepheloid Layersmentioning

confidence: 69%

“…Benthic nepheloid layers examined in the Gulf of Maine (Townsend et al 1992), Kiel Bight (Ritzrau & Graf 1992), the deep Arabian Sea (Boetius et al 2000) and the Northeast Water, an Arctic polynya , all supported greater bacterial abundance and/or biomass relative to nearby deep waters. The following are consistent with the possible nutritional advantages of the nepheloid layers that we sampled, in which yellow particles stained by DAPI were abundant: the report that such particles are rich in labile organics (Mostajir et al 1995), the positive correlation we observed between nepheloid particle and chl a concentrations, and the significantly higher concentrations of hybridizable cells in the nepheloid layers than in deep waters (Mann-Whitney U-test, p = 0.02).…”

Section: Nepheloid Layersmentioning

confidence: 96%

Abundance of Bacteria, the Cytophaga-Flavobacterium cluster and Archaea in cold oligotrophic waters and nepheloid layers of the Northwest Passage, Canadian Archipelago

Wells¹,

Deming²

2003

Aquat. Microb. Ecol.

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We used fluorescent in situ hybridization and epifluorescence microscopy to assess the distribution and diversity of pelagic microorganisms, specifically Bacteria, the Cytophaga-Flavobacterium (CF) cluster and Archaea, in the cold (-1.5 to 3.5°C) and oligotrophic waters of the Northwest Passage, Canadian Arctic, during September 2000. Total cell abundance ranged from 1.23 to 6.56 × 10 5 cells ml -1 , approximately half of which were hybridizable; Bacteria dominated the region (67 to 99.8% of hybridizable cells). CF were well-represented in the surface-water bacterioplankton, accounting for 9 to 41% of the total cell count (21 to 76% of hybridizable cells), but not in deeper populations: in nepheloid (particle-rich) layers, they accounted for only 1.6 to 5.4% of total cells (3.2 to 9.5% of hybridizable cells) despite the available substrata for attachment, a behavior common to this group. Over the entire data set, often highly significant (p < 0.001) correlations with environmental variables, including oxygen, particulate organic nitrogen (PON) and chlorophyll a (chl a) (positive) and depth, salinity and macronutrients (negative) suggested the importance of CF as aerobic heterotrophic consumers in this environment. In marked contrast, Archaea were present at very low levels (0.1 to 2.6% of total cells; 0.2 to 4.6% of hybridizable cells) in the surface waters, becoming more abundant in nepheloid layers, where they accounted for 2.3 to 13% of total cells (3.9 to 33% of hybridizable cells). Archaea correlated highly significantly (p < 0.001) with concentrations of particles and, in nepheloid layers, with PON. Over the entire data set, Archaea and Bacteria correlated significantly but oppositely to the same environmental variables of depth, salinity, oxygen and macro-nutrients, suggesting separate niches in this setting. In general, our results substantiate and extend the growing evidence for the numerical importance of CF in cold marine surface waters and further document the distribution and oceanographic context of the planktonic Archaea to include nepheloid layers.KEY WORDS: Cytophaga-Flavobacterium · CF · Archaea · Nepheloid layer · Arctic · Particleassociated Bacteria · Amundsen Gulf Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 31: [19][20][21][22][23][24][25][26][27][28][29][30][31] 2003 clivity for attachment, constituents of the CytophagaFlavobacterium-Bacteroides phylum, including the CF cluster, represented 18 to 55% of nonplastid-like ribosomal sequences cloned from bacteria associated with marine snow in Californian coastal waters (DeLong et al. 1993) and in the Adriatic Sea (Rath et al. 1998). They were also members of the communities found attached to suspended particles in the Columbia River estuary (Crump et al. 1999) and to deposited sediments in the eastern Arctic (Ravenschlag et al. 2001). CF association with pelagic particles has not been addressed explicitly in high latitude waters; however, they appear again as abundant members ...

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Microbial activity and particulate matter in the benthic nepheloid layer (BNL) of the deep Arabian Sea

Cited by 35 publications

References 37 publications

Archaea in particle-rich waters of the Beaufort Shelf and Franklin Bay, Canadian Arctic: Clues to an allochthonous origin?

Archaea in particle-rich waters of the Beaufort Shelf and Franklin Bay, Canadian Arctic: Clues to an allochthonous origin?

Swept under the carpet: organic matter burial decreases global ocean biogeochemical model sensitivity to remineralization length scale

Abundance of Bacteria, the Cytophaga-Flavobacterium cluster and Archaea in cold oligotrophic waters and nepheloid layers of the Northwest Passage, Canadian Archipelago

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